Multi-subscriber identification module (SIM) wireless devices have become increasing popular because of the versatility that they provide, particularly in countries where there are many service providers. For example, dual-SIM wireless devices may allow a user to implement two different plans or service providers, with separate numbers and bills, on the same device (e.g., business account and personal account). Also, during travel, users can obtain local SIM cards and pay local call rates in the destination country. By using multiple SIMs, a user may take advantage of different pricing plans and save on mobile data usage.
In various types of multi-SIM wireless communication devices, each modem stack associated with a subscription may store information provisioned by its respective network operator in a SIM, which may allow the SIM to support use of various different communication services. For example, various wireless networks may be configured to handle different types of data, use different communication modes, implement different radio access technologies, etc. One type of multi-SIM wireless device, referred to as a dual-SIM dual active (DSDA) device, allows simultaneous active connections with the networks corresponding to two SIMs using separate transmit/receive chains associated with each SIM.
In a DSDA device, each SIM may be associated with a separate radio frequency (RF) resource, thereby allowing the DSDA device to simultaneously connect to and communicate on both networks. However, when one subscription is inactive, the DSDA device may not be using its RF capabilities to the fullest potential.
In some DSDA devices, information stored on a SIM of a DSDA device may enable use of advanced wireless communications interface technologies. While such advanced technologies may provide increased speed to improve various user experiences (e.g., high data rates, streaming high-bandwidth media, complex applications, etc.), they may also require increased capacity on the receiver of the wireless device.
Some DSDA devices may therefore benefit from the use of multiple antennas and/or other RF receive chain components, i.e., as “receive diversity.” Specifically, in some DSDA devices, receive diversity may provide dramatic improvement in data throughput, and may prevent dropped calls in weak coverage areas. However, in order to enable receive diversity for a SIM in a conventional DSDA device, dual antenna support is required on the RF resource associated with that SIM, which may add hardware costs to the device. Further, during times in which the benefits of receive diversity may be unneeded or underutilized, the added power cost and delays associated with implementing receive diversity may not be warranted.